Installation system for pv modules

ABSTRACT

A mounting system for photovoltaic modules includes at least two profile-shaped cross rails arranged parallel to each other and configured to hold several PV modules. Each cross rail includes plane supporting surfaces. The PV module is mounted by placing it onto the at least two cross rails so that the at least two holders lay flat on the plane supporting surfaces of the at least two cross rails. The PV module is then moved in a joining direction perpendicular to the cross rails while lying on the plane supporting surfaces so that either a recess engages with an integrated protrusion or a protrusion engages with an integrated recess. A retaining safety device is disposed between at least one cross rail and its corresponding holder and is configured to counteract a move against the joining direction.

The invention relates to a mounting system by which photovoltaic modules are mountable on a supporting structure by means of holders without using any tools. The holders are adhesively affixed to the PV moduls back side. Such mounting systems are particularly required for large-scale photovoltaic on-roof installations and open area installations comprising frameless thin-film modules.

From DE 101 05 718 A1 a photovoltaic module group is known whose PV modules can be suspended into a supporting structure. Therefore, agraffes known from the facade mounting sector are provided on the back side of the PV modules forming a hook connection together with bolts on the supporting structure. From U.S. Pat. No. 5,480,494 A, PV modules are known comprising base bodies formed from metal sheet, that can be mounted to supporting structures by using various hook connections.

From DE 103 29 184 A1, a system for mounting roof construction elements is known. The system comprises several adhesion connectors the corresponding joining elements are suppose to act according to the hook-and-loop principle. The joining elements can be arranged on the back side of the PV module in a self-adhesive manner.

From DE 10 2004 055 187 A1, profile rails for photovoltaic modules are known that can be adhesively affixed onto the back side of a frameless PV module by using a silicone adhesive and that can be screwed with a supporting structure.

From U.S. Pat. No. 5,143,556 A, an elevation for a PV module field is known, the modules of which can be mounted on supporting rails by using holders that are adhesivly affixed onto the modules' back side. Each holder shall encompass the bead at a bolt's head in a clip-like manner, wherein the bolts are singly sticking out from the supporting rails.

With increasingly larger module formats, those mounting systems known do not any longer fulfill the manufacture and installation requirements of industrial photovoltaic plants. Furthermore, some of the known systems are not designed for high wind and snow loads.

Thus, one object of the invention is to develop a mounting system for PV modules by which particularly large-surface frameless thin-film modules are hold carefully and safely with consideration to high wind and snow loads. Additionally, the mounting system shall be installable without using any tools and easier to be manufactured.

The solution of the object is achieved by means of the features given in claim 1. According to claim 1, the mounting system comprises preferably two or even more profile-shaped cross rails that are arranged in parallel to and at a distance to each other and which are provided for holding several PV modules. The cross rails that are preferably identical in construction can particularly be made of an aluminum material by using an extrusion method such as extrusion molding. It is also conceivable to produce the cross rails in a profile-shape by using other materials such as, e. g., wood or steel, and by using other methods.

The cross rails mainly provide a retaining function for the holders and can thus be supported by additional supporting structure for supporting several PV modules in a kind of sandwich construction. However, it is preferably possible that the cross rails at the same time provide the function of a load bearing girder for several PV modules. It is essential for the retaining function of the cross rails that they run in a cross direction within a substructure. In the field of photovoltaic systems this means that the cross rails are aligned in a cross direction to the PV moduls' edges running downwards and/or to the slope line of the PV modules, i. e. to the direction of downhill force. In slant arrangement, the cross rails are thus recognized easily in that they are—preferably horizontally—arranged in different heights.

Additionally, each of the cross rails comprises a plane supporting surface that can also be composed of several parts. The supporting surfaces of the cross rails can thereby build a common inclined plane that is preferably parallel to the module plane. The joining direction then preferably runs downwards and in parallel to the said plane. However, it is also conceivable to provide the supporting surfaces stepwise one below the other. In the case of a common inclined plane, the said plain can be inclined as regards a horizontal plane, particularly in a solar-energetically suitable angle ranging from 20 to 50 degrees.

The mounting system further comprises several holders which are preferably identical in construction and which are each fixed or fixable to the back side of PV module by using an adhesive agent. The adhesive agent may particularly be a silicone-based adhesive which has proven to be reliable in the field of construction engineering for the material combination of metal and glass even under extreme weather conditions. Two-component silicone adhesives are thereby preferred. It is also possible to use, for example, epoxy resin, polyester resin, poly urethane or acrylate adhesives. Furthermore, the adhesive agent can also be provided as a support layer covered with adhesive on both sides. Such a support layer may particularly be embodied as a double sided adhesive pad preferably corresponding to the holder's dimensions. The support layer may have been applied prior to connecting the holder with the module's back side, i. e. in a pre-manufactured manner, onto the holder or, alternatively, onto the PV module, and provided with a removable protective film in a appropriate manner.

By means of the holders, the PV module can be mounted to the cross rails for which purpose each cross rail has at least one holder associated or allocated therewith and each holder has a recess and each cross rail has an integrated protrusion. Alternatively, it is also possible that each holder has such a protrusion and each cross rail has an integrated recess. For mounting, the PV module is then firstly placed onto the cross rails such that the holders lay flat on the supporting surfaces of the cross rails. Herefor, the holders each preferably comprise a plane contact surface at which the holders can be placed onto the supporting surface of the respective cross rail under plane contact and are correspondingly guided in a shiftable manner thereon. Secondly, while laying thereon, the PV module is shifted in a joining direction perpendicular to the cross rails, wherein the recesses and the protrusions are more and more engaging with each other during shifting. Moreover, the joining direction is parallel to the supporting surfaces and is preferably running inclined downwards in the direction of the slope line and/or parallel to an outer edge of the PV module running downwards.

The recess of a holder can particularly be embodied as an indentation of a hook. Such a hook is preferably sticking out from the contact surface of the holder. The protrusion of the respective cross rail operating as a counterpart may advantageously be embodied as an overhang of an undercut groove that is integrated within the cross rail's profile and into which the hook is inserted during the placing. The opening slot of such an undercut groove can separate the supporting surface of the cross rail in preferably two partial areas having approximately the same width.

Alternatively, it is also possible that the recess is provided as an undercut of a hook integrated within the respective cross rail and that the protrusion is provided as an overhang of an undercut groove within the respective holder. Here, the hook can stick out from the supporting surface of the cross rail and the undercut groove can separate the contact surface of the holder.

Moreover, the mounting system according to the invention comprises a retaining safety device. The retaining safety device is provided between at least one cross rail and a holder associated therewith and counteracts a possible backshift of the holder against the joining direction, in particular in the case of wind suction. Such a retaining safety device may, for example, be designed as an snap-fit, or snap-in, connection comprising several joining positions and/or as a blocking device.

The invention comprises several advantages. Thus, the mounting system according to the invention is particularly suitable with regard to manufacture and mounting. The holders can be fixed or attached, preferably in a factory-provided manner, to the back side of the PV module by using an automated and controlled process by means of adhesive bonding. However, alternatively, it is also conceivable to mount the holders thereto on-site. In case the adhesive agent such as a silicone adhesive has elastic properties, moreover stresses resulting from temperature and mounting can be absorbed and the PV module can be supported in a cushioned manner.

As the protrusion or the recess, respectively, has already been integrated within the profile-shaped cross rail, the manufacture of the cross rails is particularly easy. Thus, the latter may preferably be manufactured by extrusion molding or roll forming. Furthermore it is possible in an easy way to design the cross rails with a very high bearing capacity so that the cross rails may support several PV module over a wide span width.

Because of the protrusions or the recesses, respectively, being integrated in the cross rails or rather extending continuously therein, it is possible upon installation to mount the PV module at any arbitrary position along the cross rails. Moreover, the installation is carried out without using any tools and in a particular ergonomic way. So the joining process is divided in a free placing onto the plane supporting surfaces of the cross rails and a subsequent smoothly shifting in a downward direction. After placing and if necessary, the PV modules may further be shifted into another mounting position in parallel to the cross rails. Dividing the joining process in the aforementioned manner is particularly advantageous for large-surface and thus accordingly heavy PV modules.

The plane supporting surfaces offer great advantages as regards statics. So every holder is resting on the associated cross rail with a comparatively large contact area whereby a correspondingly stable and easily calculable load transmission will be possible. This particularly applies for high snow and wind loads. The mounting system is thus particularly suitable for frameless thin-film modules with a surface area of significantly more than one square meter.

A further essential advantage is that tolerances of the distance of the cross rails and the holders resulting from manufacture and mounting can be compensated. In case the cross rails are, for example, spaced apart from each other too broad or too narrow, this can be compensated by means of a various deep engagement of recess and protrusion. Thereby, it is of particular advantage that, independently from the depth of engagement, the holders always rest on the plane supporting surfaces having plane contact and can be shifted thereon depending on the actual distance situation.

Furthermore, the retain safety device prevents that the recess and the protrusion being released from their engagement in the direction against the joining direction, particularly under extreme wind conditions. The said retaining safety device may alternatively or additionally also be designed as an anti-theft device.

Moreover, not only the cross rails but also the holders may be mass-produced in a simple manner by using an extrusion molding process. So it is preferred when the holders are substantially embodied in form of an extrusion molded part or rather being cut off from an extrusion molded profile correspondingly. As for the cross rails, the recess respectively the protrusion can be integrated by extrusion as well.

In summary, with respect to increasingly large-scale and more cost efficient PV modules, the mounting system according to the invention makes a significant contribution to supporting structures for industrial photovoltaic systems that are easier to manufacture and easier to mount.

In a preferred embodiment, the holders are arranged at positions within the inner or interior surface area of the PV module's back side at a distance from the outer contour of the PV module. Thereby, it is appropriate to arrange the holders in such a way that the PV module undergoes a deflection as low as possible in its position of use. In this way, the module may be particularly preserved and its bearing properties for snow loads may be increased. If there are exactly four holders provided for the PV module, the holders or rather their centers may be arranged inwardly at a distance to the outer edges of the PV module by preferably 17% to 27% of the distance towards the respective opposite outer edge. According to a rule of Bessel, a distance to the center of the holders of about 22% is particularly advantageous.

For arranging the holders onto the back side of the PV module, a mounting template can be provided determining the positions for arranging the holders relative to the outer contour of the PV module. By using such a mounting template, the holders can also still be adhesively affixed to the PV modules at the construction site of the photovoltaic system, preferably by using the aforementioned double sided adhesive pads. When using double sided adhesive layers, it is further possible to affix the latter in a factory-provided manner exactly at the desired positions onto the back side surface of the PV modules. In this way, the holders can be positioned on the adhesive layers at the construction site after drawing off a corresponding protective film, whereby the use of a mounting template can be avoided. Thereby, the adhesive film mark those positions for arranging. It is advantageous for an easy mounting and exact positioning process if the adhesive layer respectively corresponds with the outer outline of the holders' adhesion surface being provided therefore.

In a further preferred embodiment, the holders each comprise a plane supporting body or structure having a contact surface and an adhesion surface being parallel thereto. The contact surface and the adhesion surface, or surface for adhesion, are preferably plane. The supporting body or rather the adhesion surface thereof may additionally have a rectangular format, whereby the longer side thereof is preferably aligned in parallel to a longer side of an optionally rectangular PV module. It is of course also possible to provide the supporting body with other forms, particularly also with square or circular adhesion surfaces. In each case, the adhesion surfaces of the holders respectively the supporting bodies that have to be provided with an adhesive agent are sufficiently large in order to retain the PV module safely and to support it gently. In a particular advantageous development, the plane supporting bodies narrows towards the outer edges of its adhesion surfaces. This means that the material thickness behind the adhesion surface diminishes from the center or from a central area of the holder or rather its supporting body to its outside, preferably in a continuous manner. Due to this diminution, the rigidity of the holder, i.e. its supporting body reduces towards its outside, thus preventing a sudden rigidity alteration between the supported and the unsupported areas of the PV module. Rigidity steps and local stress peaks resulting therefrom may thus be avoided effectively, thus preserving the PV module particularly with respect to high snow loads and dynamic wind loads. Additionally, in this way, thrust and shear forces acting on the adhesion may be reduced. A supporting body designed in the said way can particularly have a trapezoid-like and thus extrudable cross section or can be shaped like truncated pyramid having four or more edges or can be shaped similar to a truncated cone. Other shapes for the supporting bodies are conceivable in which the material thickness reduction towards the outside is not linear but, for example, parabola- or hyperbola-shaped. This can be of particular advantage for rotationally symmetrical shapes.

In a preferred embodiment, the recesses and the protrusions appropriately engage with each other in a form-fitting manner when shifting in the joining direction. Thereby, preferably a sliding clearance is provided such that the recesses and the protrusions inter-engage under sliding fit. Therefore, the protrusions and the recesses are preferably designed rigid. In this way, a particular stable and easily calculable connection between the holders and the cross rails is generated comparable to a groove-tongue-connection having a sliding fit. Thus, a lifting of the holders off the supporting surfaces is not possible even under extreme wind suction conditions.

Moreover, it is possible that the recess and/or the protrusions are at the same time limited by the supporting surface of the cross rail or of the contact surface of the holder, respectively. Furthermore, it can be advantageous if a sliding fit is provided between the contact surface as well as an opposite parallel flank thereto at the protrusion or the recess of the holder, on the one hand, and the supporting surface as well as an opposite parallel flank thereto at the protrusion or the recess of the cross rail, on the other hand. Hereby, the flanks can be directly or diagonally opposite to the supporting surface respectively to the contact surface. It is essential for the sliding fit that the respective flank appropriately counteracts to the supporting surface or contact surface, respectively.

Alternatively or additionally, it is possible that the recesses and the protrusions engage with each other in a force-transmitting and form-fitting manner. Therefor, at least one flank of the recesses and/or at least one flank of the protrusions may be designed elastically, for example, in form of an integrated bendable bar, or may abut against elastic elements, in particular against a metal spring. Such a spring can be arranged between the flank of a protrusion and the flank of a recess. It is also conceivable to design the protrusion completely in form of a bendable bar. In each case it is advantageous for compensating distance tolerances if the maximum possible engagement between the recesses and the protrusions is dimensioned appropriately, in particular at least 4 mm. While engaging there exists preferably always a sliding fit.

In a further preferred embodiment, for retaining safety in an arresting manner, a snap-fit, or snap-in, connection comprising several successive joining positions is provided between at least one cross rail and a holder associated therewith. During the shifting process, the joining positions here follow successively in the aforementioned joining direction, preferably in equal distances. In this way, the cross rails and the holders can be connected to each other free from play despite any distance deviation resulting from manufacture or mounting. Thereby, it is possible to design the snap-fit connection that the latter operates against the joining direction in a locking manner, whereby disassembling is not possible any more without further efforts.

The snap-fit connection can particularly comprise a row of teeth integrated within the cross rail and a snap-fit hook elastically arranged at the respective holder, wherein the snap-fit hook is interacting with the row of teeth. Alternatively, it is conceivable to provide the snap-fit connection in the way that an elevation is integrated within the cross rail, for example, in form of a hooked nose, and an elastically arranged row of teeth is provided at the holder, the row of teeth interacting with the elevation. Hereby, it is also possible to provide several successive elevations, preferably in form of a second fixed row of teeth interacting with the elastic row of teeth.

In a particular development, it is furthermore possible to arrange the elements of the snap-fit connection, such as in particular a snap-fit hook and a row of teeth, at the flanks of the protrusions and/or of the recesses. Moreover, it is possible to arrange the elements of the snap-fit connection such that the elements limit the respective protrusions and/or recesses. Hereby, it can be of particular advantage if one of the elastic elements of the snap-fit connection presses the holder against the supporting surface of the cross rail.

In a further preferred embodiment, for retaining safety in an blocking manner, a blocking element is disposed at at least one holder, wherein the blocking element, in a release position, allows a shifting of the holder in joining direction over the supporting surface of the cross rail associated therewith and, in a blocking position, blocks a shifting against the joining direction. In particular, the blocking element can be a latch arranged at the holder interacting with a limit stop at the cross rail. Thereby, it can be of advantage if, in the release position, the latch is turned in a recess provided within the contact surface of the holder and turned out while shifting in the joining direction and abuts against the limit stop of the cross rail in the blocking position.

In a particular preferred embodiment of the mounting system, for each PV module, four point-like acting holders and exactly two cross rails are provided, wherein two holders are associated with one of the two cross rails respectively. Alternatively, it is possible that each of two cross rails is associated by only one line-like acting holder such that the PV module is supported only by two holders. Depending on the module size, it is furthermore possible to provide more than two cross rails and also more than two holders per cross rail and PV module. Thus, it is particularly advantageous for large-surface PV modules to provide two or three cross rails and each three holders. For module formats having an area of several square meters, more holders and cross rails are possible accordingly.

In the following, several exemplary embodiments of the invention will be explained in detail with respect to drawings, wherein:

FIG. 1 is a lateral view of an elevated PV module field,

FIG. 2 is a view perpendicular onto the plane of the PV module field according to FIG. 1,

FIG. 3 is a top view onto a mounting template,

FIG. 4 shows a mounting system according to FIG. 1 prior to the joining process,

FIG. 5 shows a detail of the mounting system according to FIG. 4,

FIG. 6 to FIG. 9 illustrate the joining process of the mounting system according to FIG. 4,

FIG. 10 is a perspective view onto the mounting system according to FIG. 1,

FIG. 11 shows a variant of the mounting system according to FIG. 1 in a detailed view,

FIG. 12 shows a variant of the mounting system according to FIG. 1 in a detailed view,

FIG. 13 shows a variant of the mounting system according to FIG. 1 in a detailed view,

FIG. 14 and FIG. 15 show a variant of the mounting system according to FIG. 1.

At first, FIG. 1 and FIG. 2 schematically show how the mounting system according to the invention is integrated within an elevated PV module field. The PV module field is composed of six PV modules 1 that have a rectangular format, are identical in construction and are embodied in form of frameless thin-film modules. The PV modules 1 are elevated onto a supporting structure in an inclined manner. The supporting structure comprises two high posts 4 a and two low posts 4 b as well as two inclined girders 3 each arranged above the posts 4 a and 4 b in an inclined manner. The two inclined girders 3 hereby form a inclined installations plane that is inclined with respect to a horizontal plane 6 in an angle α of about 30°. Moreover, the installation plane is parallel to the module plane so they have a downhill force direction and slope line corresponding to the angle α and represented by the arrow 7.

The supporting structure additionally comprises four cross rails 2 that are identical in construction. The cross rails 2 are arranged on the two inclined girders 3 and run in a cross direction thereto. The four cross rails 2 are spaced parallel to each other, wherein two adjacent cross rails 2 each hold and support three of the PV modules 1 in a row. Thus, two module rows are provided with three PV modules 1 each. Furthermore, the cross rails 2 are profile-shaped, i. e. they have a uniform cross section all over their length as can be seen in detail in FIG. 4. The mounting system according to the invention comprises the said cross rails 2.

It is also possible to mount the cross rails 2 onto a pitched roof. It is essential for the function of the mounting system still to be explained that the cross rails 2 as shown run in a cross direction to the inclined girders 3. Correspondingly on a pitched roof, the cross rails would be aligned in a cross direction to the slope line of the pitched roof. In a slanted arrangement, cross rails can also be recognized in that the latter run in different heights horizontally or approximately horizontally. In case of a terrain that is considerably slanting in an east west direction, the cross rails can also significantly deviate from the horizontal. In each case, the arrow 7 is preferably aligned with the direction of the downwards running edges of the PV modules 1, independently from the slope line.

Furthermore, FIG. 1 and FIG. 2 show that each PV module 1 is connected with two of the cross rails 2 via four holders 5, wherein each of that two cross rails 2 is associated or allocated by two of the holders 5. As will be explained in more detail in FIG. 4, the holders 5 are fixed or attached to the back side 11 of the respective PV module 1 by using an adhesive. It is also essential that the holders 5 are arranged at a distance to the outer contour 4 at positions within the inner or interior surface area of the back side of the respective PV module 1. According to the theory of Bessel, the positions are thereby arranged at a distance from the outer contour 4 of the PV module 1 inwardly by a factor of 0.22 times the side length towards the respective opposite module edge which is illustrated by the distance arrows d1 and d2. Thus, the PV module 1 which is supported by the holders 5 undergoes a deflection and/or bending load that is as low as possible. The holders 5 have preferably yet been adhesively affixed in an industrial manufacturing process onto the back side of the PV modules 1 in a factory-provided manner.

Alternatively, it is possible to connect the holders 5 provisionally by using a mounting template 8 according to FIG. 3 with a PV module 1. The mounting template 8 can be made from a plane metal sheet and is designed grid-like and comprises limit stops 10 at the outer edges thereof by which the mounting template 8 can always be placed congruently onto a PV module 1 or rather can be attached to the outer contour 4 thereof that is illustrated by means of a dashed line. Moreover, the mounting template 8 comprises four openings 9 that correspond to the holders 5 format and are arranged at the positions defined for the holders 5. By means of insertion into the openings 9, the holders 5 can be positioned in a precise and simple manner on a construction site and can be fixed to the back side of the PV module 1 preferably by using double sided adhesive pads. It is also possible that the mounting template 8 also determines the thickness of the adhesive layer 12 according to FIG. 4.

FIG. 4 shows the mounting system according to the invention comprising the cross rail 2 and the holder 5 together with the PV module 1 at the position D1 according to FIG. 1 and FIG. 2 prior to the joining process. As can be seen, the holder 5 comprises a flat plate-like supporting body 13 or structure that is limited by a plane adhesion surface 14 on top and by a plane contact surface 15 a, b at the bottom. The adhesion surface, or surface for adhesion, 14 and the contact surface 15 a, b are parallel to each other and are spaced flat. As can be seen from FIG. 2, the adhesion surface 14 has a rectangular format and an area of about 60×150 mm in the present embodiment. In this connection, flat or plane particularly means that the material thickness of the supporting body 13, here for example of about 8 mm, is significantly smaller, preferably smaller by a multiple more like in case of plates, than the length of the rectangular sides of the adhesion surface 14. Moreover, due to static reasons, the longitudinal edges of the adhesion surface 14 are aligned in parallel to the longitudinal edges of the rectangular PV module 1.

The holder 5 is fixed to the plane back side 11 of the PV module 1 at its adhesion surface 14 by using an adhesive agent. The adhesive agent can schematically be seen as a flat adhesive layer 12 between the back side 11 of the PV module 1 and the adhesion surface 14. As the holder 5 can particularly be made of a metal material, preferably of an aluminum, and the back side 11 of the PV module 1, designed in form of a frameless thin-film module, can usually be made of glass, a two-component silicone adhesive that has been proven for the said material combination in construction engineering and for outdoor environment can be used for adhesive fixing. Furthermore, such an adhesive can have a cushioning and stress-compensating effect.

Furthermore, it can be seen that the supporting body 13 comprises a trapezoid-like cross section, wherein the contact surface 15 is smaller than the adhesion surface 14 and is arranged approximately in the center and beyond the adhesion surface 14. The material thickness of the supporting body 13 thus reduces continuously beginning from the left and the right edge of the contact surface 15 a, b towards the left and the right edge of the adhesion surface 14 by means of two slants 17. By this diminution, also the rigidity of the holder 5 reduces towards the outside, whereby a sudden rigidity alteration between the supported and the unsupported area of the PV module 1 is avoided. Alterations in rigidity and local stress peaks resulting therefrom can thus effectively be avoided, preserving the PV module 1 particularly against high wind and snow loads.

Additionally, the cross rail 2 associated with the holder 5 is shown in FIG. 4. The cross rail 2 comprises a special cross section that is uniform over the entire length thereof. The cross section can be divided into two areas. A lower area providing a high supporting strength for load transmission; and an upper area having special retaining features for mounting the holders 5.

In the upper area of the cross rail 2, two bars 18 a, b projecting at the left and at the right side, the bars 18 a, b each providing a partial surface of a common plane supporting surface 19 a, b towards the top. The supporting surface 19 a, b is interrupted approximately in the center by the opening slot of an undercut longitudinal groove 20. The side walls 21 a and 21 b of the said undercut longitudinal groove 20 connect the projecting bars 18 a, b with the lower area of the cross rail 2. There, the cross rail 2 comprises a trapezoid-like hollow section having a slant bar 22 both at the left side and at the right side as well as having a bottom chord 23 and a top chord 24. The bottom chord 23 and the top chord 24 are arranged in parallel to each other, wherein the bottom chord 23 is broader than the top chord 24. By means of the bottom chord 23, the cross rail 2 rests on the inclined girder 3 according to FIG. 1 and FIG. 2 in a cross direction thereto. Moreover, the bottom chord 23 serves for fixing the cross rail 2 to the inclined girder 3, whereby extensions are formed on both sides of the bottom chord 23 that are tangible by clamps not explicitly shown here. The top chord 24 is also the bottom of the undercut longitudinal groove 20. The two slant bars 22 are inclined inwardly in an angle of 60 degrees and intersect in their extension represented by means of a dashed line in an intersection line 25 which can be seen as a point. The said intersection line 25 runs approximately in the center between the two parts of the supporting surface 19 a, b. In complete, the side walls 21 a and 21 b of the undercut longitudinal groove 20 form an approximately X-shaped cross section together with the two slant bars 22. Although the cross rail 2 has statically optimized supporting properties, it is possible to reduce the cross rail 2 to the upper area provided for mounting the holders 5 and to attach it onto another suitable supporting structure such as particularly a lattice girder or a wooden beam.

Furthermore, in FIG. 4 can be seen that not only the cross rail 2 but also the holder 5 has an extrudable form and can thus particularly be manufactured by using an extrusion molding method. Being substantially embodied in form of extrusion molded parts, the holders 5 can be easily produced even in different widths by cutting of only one profile string and thus be adapted to different formats and supporting properties of PV modules when indicated. Moreover it can be seen well at this position, once the holder 5 is placed the top surface of the inclined girder 3, the supporting surfaces 19 a, b, the contact surface 15 a, b, the adhesion surface 14 and the back side 11 of the PV module 1 are in parallel to each other.

As particularly can be seen in detail from FIG. 5, a rigid hook 26 sticking out from the contact surface 15 a, b, approximately in the center thereof. The hook 26 is designed as an L-shaped rail, not shown in detail, running over the entire width of the holder 5 according its cross section. The hook 26 comprises an undercut, i. e. a recess 27 in form of a groove arranged between the hook's 26 hook protrusion and the contact surface 15 b. The recess 27 has a rectangular cross section and is limited by the contact surface 15 a, b at its top side and by a flank 28 being parallel thereto at its bottom side. The counterpart of the recess 27 is the protrusion 29 provided at the cross rail 2 and designed in form of an overhang of the undercut longitudinal groove 20. The protrusion 29 also has a rectangular cross section and is limited by the supporting surface 19 b at its top side and by a flank 30 being parallel thereto at its bottom side. The rectangular cross sections of the recess 27 and of the protrusion 29 correspond to each other. And as can be seen in the following FIG. 8 and FIG. 9, the recess 27 and the protrusion 29 can be shifted into each other in a form-fitting manner, wherein the joining path runs inclined downwards in the direction of the arrow 7. Preferably, the front side 31 of the protrusion 29 here acts as an end stop for the back side 32 of the recess 27.

Moreover, FIG. 5 shows in detail that a snap-fit hook 33 in form of a bendable bar having a snap-fit hook sticking out, is additionally provided at the rigid hook 26. The snap-fit hook 33 is integrally attached in the area of the head of the rigid hook 26 and also runs, not shown in detail, over the entire width of the holder 5 according its cross section. The counterpart of the snap-fit hook 33 is a row 34 of teeth integrated within the bottom of the undercut longitudinal groove 20. The single teeth or elevations of the row 34 of teeth are running in parallel to the cross rail 2. The joining direction of the said snap-fit, or snap-in, connection thereby corresponds to the joining direction of the aforementioned recess 27 and the protrusion 29 according to arrow 7.

Furthermore, a blocking element embodied as a latch 35 can be seen in FIG. 5. The latch 35 can be pivotably turned in and out of a recess within the contact surface 15 a. By means of a spring element 37, the latch 35 is pretensioned in a stable blocking position against a small limit stop provided at the side of the recess 36. In the release position according to FIG. 7, the latch 35 is completely turned into the recess 36 such that the latch 35 does not protrude from the contact surface 15 a. In its blocking position, the latch operates together with a limit stop 38 provided at the left side of the undercut longitudinal groove 20 as can be seen from FIG. 9. Moreover, it has to be mentioned here that the holder 5—except to the latch 35 and the spring element 37—is designed as an extrusion molded part, wherein the hook 26 having the recess 27, the snap-fit hook 33 and the recess for the latch 35 have already been integrated by means of extrusion.

FIGS. 6 to 9 illustrate the joining process of the mounting system, i. e. how the holder 5 is mounted into the upper area of the cross rail 2. Here, the PV module 1 and the adhesive layer 12 are not shown. Furthermore, the reference numerals according to FIG. 1 to FIG. 5 additionally apply. Moreover, for better comparability of the single joining positions, the mounting system is represented horizontally in the drawings, wherein it has to be noticed that the position according to FIG. 6 corresponds to the position according to FIG. 5. For reasons of clarity, the arrow 7 representing the slope line, the inclination angle α of 30 degrees and a further horizontal plane 6 are shown.

FIG. 6 illustrates an initial position prior to the joining process, in which, for example, two assemblers manually hold the PV module 1 at a distance above the cross rail 2. It can be seen that the latch 35 is turned out of the recess 36 and the snap-fit hook 33 is relaxed. After performing a first freehand motion 40 for placing the holder 5 the position according to FIG. 7 is reached.

According to FIG. 7, the holder 5 is now placed with its contact surface 15 a, b onto the supporting surface 19 a, b of the cross rail 2 having sufficiently plane contact and thus resting in a statically appropriate way. While placing the holder 5, the hook 26 is inserted into the undercut longitudinal groove 20 of the cross rail 2. In order to allow distance tolerances to the parallel adjacent cross rail 2 according to FIG. 1, the undercut longitudinal groove 20 is designed wider than the hook 26 accordingly. Furthermore, it can be recognized that the latch 35 has been turned into the release position under the tension of the spring 37, that is not shown in detail anymore, while placing the holder 5 onto the supporting surface 19. In this position, a free shift of the holder 5 on the supporting surface 19 a, b both in and against the slope line 7 by a small extent for compensating distance tolerances is possible without thereby inter-engaging the recess 27 and the protrusion 29. Furthermore, the snap-fit hook 33 abuts against the bottom of the undercut longitudinal groove 20 so that the snap-fit hook 33 is pretensioned by a little amount. Additionally, in this position it is particularly easy to shift the PV module 1 on the supporting surfaces 19 a, b parallel to the cross rails 2, if necessary, into a proper mounting position, for example, in order to obtain a determined distance to an adjacent PV module.

A second joining motion 41 finalizes the joining process and is carried out by means of shifting the holder 5 perpendicular to the cross rail 2 and parallel to the supporting surface 19 a, b in the direction of the arrow 7 downwards. Thereby, the recess 27 of the hook 26 is shifted over the protrusion 29 of the cross rail 2 in a proper form-fitting manner, wherein an appropriate sliding clearance is provided between the flank 28 of the recess 27 and the flank 30 of the protrusion 29. It is essential that the recess 27 and the protrusion 29 are engaged with each other not only by means of a simple hook connection but also by means of a kind of groove-tongue-connection comprising a sliding fit. The said sliding fit between the holder 5 at its contact surface 15 a, b as well as the opposite flank 28 parallel thereto and the cross rail 2 at its supporting surface 19 a, b as well as the opposite flank 30 parallel thereto is present over the whole compensating range. Thus, the holder 5 and the cross rail 2 are guided to one another between the maximum positions according to FIG. 8 and FIG. 9 along the said surfaces. The protrusion 29 is also limited by the supporting surface 19 a; and the recess is also limited by the contact surface 15 a. During the inter-engagement process of the recess 27 and the protrusion 29, there occurs a sliding fit overlap preventing a lifting off of the holder 5 from the cross rail 2. The overlap is dimensioned such that distance tolerances of, for example, ±2 mm can be compensated between the two cross rails 2 and/or the respective holders 5 according to FIG. 1 and FIG. 2.

Additionally, during the second joining motion 41, the snap-fit hook 33 engages into the row 34 of teeth. To this the length of the row 34 of teeth is adapted to the size of the desired tolerance compensation. Depending on the length of the shift, i. e. depending on the deviation from the nominal distances between two adjacent cross rails 2 and/or the holders 5, the snap-fit hook 33 can thereby take on one of several successive joining positions, wherein a grid spacing for the row 34 of teeth of less than one millimeter is provided here. Accordingly, the said snap-fit connection of the snap-fit hook 33 and the row 34 of teeth provides a finely sub-divided arresting possibility effectively inhibiting an unintended shift or a motion play, both in and against the direction of the arrow 7. However, the snap-fit connection allows disassembling such that the snap-fit connection of all four holders 5 can be overcome by using sufficiently high manual force. It is also conceivable to block a motion against the second joining motion 42 and the arrow 7, when using an appropriate asymmetrical design of the tooth flanks, particularly when using a saw tooth profile design. During the second joining motion 41, the latch 35 additionally turns out of the recess 36, preferably in the position, in which the snap-fit hook 33 reaches the first joining position on the row 34 of teeth. After the second joining motion 41, the holder 5 can be shifted either as far as the bottom 32 of the recess abuts against the front side 31 of the protrusion 29 according to FIG. 8 or as this is effected at an opposite holder 5 of the parallel adjacent cross rail 2. Alternatively or additionally, the front side of the hook protrusion can abut against the opposite side wall 21 b of the undercut longitudinal groove 20.

FIG. 8 shows the mounting system in a first of two maximum positions. A further shifting inclined downwards in the direction of the arrow 7 is not possible any more. Furthermore, it can be seen that the snap-fit hook 33 rests in the last joining respectively snap-fit position of the row 34 of teeth. This position can be reached when the two adjacent cross rails 2 are spaced from each other by the nominal distance. It is also conceivable that the shown position will firstly be reached long after the mounting process, particularly when the module is powerfully pushing downwards due to snow load. Besides, in this position, the foot of the hook 26 is arranged in a statically appropriate way approximately in the center of the intersection line 25 of the cross rail 2 according to FIG. 4. Furthermore, it can be seen that the latch 35 has now been turned out. If the snap-fit connection should be overcome upwards, for example, due to a theft attempt or in case of particularly high wind suction, according to FIG. 9, the latch 35 abuts against the limit stop 38 arranged at the left side of the undercut longitudinal groove 20 of the cross rail 2. The distance 42 that can be seen from FIG. 8 between the latch 35 and the limit stop 38 is thereby as large as the desired tolerance compensation.

FIG. 9 shows the mounting system in the second maximum position. The latch 35 abuts to the limit stop 38, whereby further shifting against the original joining motion 41 is blocked and, thus, dismounting the holder 5 out of the cross rail 2 is not possible without further efforts. For releasing the latch 35, a special tool is required. In practice the holder 5 will abut to the cross rail 2 according to FIG. 8 or, due to distance tolerances, will be located between the two maximum positions according to FIG. 8 and FIG. 9. It is essential that the sliding fit overlap between the recess 27 and the protrusion 29 always remains during compensating the said tolerances, whereby the holder 5 and the PV module 1 cannot lift off undesirably from the supporting surface 19 a, b even under extreme wind conditions. With respect to FIG. 8 and FIG. 9, it can be further seen that the contact surface 15 a, b is dimensioned such that the latter covers the supporting surface 19 a, b in a statically appropriate manner over the entire shifting extent. It goes without saying that adjacent holders and the cross rails associated therewith have a corresponding distance according to FIG. 1.

For illustration purposes, FIG. 10 shows the cross rail 2 and the holder 5 of the mounting system according to the invention in the maximum position according to FIG. 8 in a perspective view. Here, the cross rail 2 is only shown in the area of the holder 5. The aforementioned reference numerals apply additionally.

FIG. 11 shows a variant of the mounting system according to FIG. 1 to FIG. 10 as regards the snap-fit connection. Unless not shown otherwise, the reference numerals apply correspondingly. The shown position corresponds to the position according to FIG. 9. It can be seen that the snap-fit connection consisting of the elastic snap-fit hook 33 and the rigid row 34 of teeth is now arranged at the level of the contact surface 15 b and of the supporting surface 19 b, respectively. To this, the snap-fit hook 33 sticks out from the foot of the rigid hook 26 approximately perpendicular and is received by a recess 50 in the supporting body 13 that is open to the contact surface 15 b. The row 34 of teeth is integrated within the supporting surface 19 a of the cross rail 2. The snap-fit hook 33 and the row 34 of teeth can be engaged to each to other in several successive joining positions in the direction of the arrow 7 such as is described in FIG. 4 to FIG. 9. Opposite to the flank 28, the recess 27 of the holder 5 is limited by the snap-fit hook 33. And, opposite to the flank 30, the protrusion 29 of the cross rail 2 is limited by an insertion slant 51 and subsequently by the row 34 of teeth. Accordingly, the recess 27 and the protrusion 29 do not only engage with each other in a form-fitting manner but in a force-transmitting and form-fitting manner. However, a sliding fit for deviations of nominal distances in the desired compensation range is provided between the contact surface 15 a, b as well as the diagonally opposite flank 28 on the side of the holder 5 and the supporting surface 19 a, b as well as the opposite flank 30 on the side of the cross rail 2. The holder 5 and the cross rail 2 are guided to one another along those surfaces while inter-engaging. The advantage of this variant is that the snap-fit hook 33 is protected from damage within the recess 50. Furthermore, the plane head surface of the hook 26 is better apt for stapling and packaging, in particular if the holders 5 have already been pre-assembled at the PV module 1 in a factory-provided manner.

FIG. 12 shows a further variant of the mounting system according to FIG. 1 to FIG. 10 as regards the snap-fit connection. Unless not shown otherwise, the reference numerals apply correspondingly. The shown position corresponds to the position according to FIG. 8. The snap-fit connection comprises a row 61 of teeth elastically arranged at the hook 26 and a row 62 of teeth rigidly arranged at the protrusion 29. The rows of teeth 61 and 62 can be engaged in several joining positions, wherein the joining positions succeed to each other in the direction of the arrow 7 again. For elastically arranging the row 61 of teeth, there is provided a bendable bar 63 that is arranged at the hook protrusion of the hook 26 and bears the row 61 of teeth. Together with the contact surface 15 b, the row 61 of teeth hereby limits a recess of the hook 26 that is filled with the protrusion 29 in the position as shown. The row 61 of teeth represents the lower flank of the said recess and is opposite to the supporting surface 19 b. The protrusion 29 is limited by the rigid row 61 of teeth at its lower flank and furthermore at the opposite side by the supporting surface 19 b. A further difference of this variant is that the holder 5 also abuts with the head of its hook 26 against the bottom of the undercut longitudinal groove 20. This can have static advantages in addition.

FIG. 13 shows a further variant of the mounting system according to FIG. 1 to FIG. 10 as regards the snap-fit connection. Unless not shown otherwise, the reference numerals apply correspondingly. The position shown corresponds to the position according to FIG. 8. The snap-fit connection comprises a snap-fit hook 70 sticking out from the lower flank 30 of the protrusion 29. A row of teeth 71 acts as a counterpart and being arranged elastically at the hook 26 via a bendable bar 73 such as the row of teeth 60 according to FIG. 12. The essential difference to the variant according to FIG. 12 is that the snap-fit connection is followed by a sliding fit between the two flanks 30 and 28 such that the recess of the hook 26 and the protrusion 29 of the cross rail 2 are additionally engaged with each other in a form-fitting manner as described in FIG. 4 to FIG. 9. Thus the hook protrusion and the undercut longitudinal groove 20 are provided broader accordingly. Moreover, the bendable bar 73 can tension the holder 5 against the supporting surface 19 a, b.

FIG. 14 and FIG. 15 show the cross rail 2 and one holder 5 of a further mounting system prior to the joining process and after the joining process. The mounting system is comparable to the variant according to FIG. 11 such that only essential common features and differences will be explained and the reference numerals analogously apply. The supporting body 13 of the holder 5 comprises four continuous recesses 80, 81, 82 and 83. By means of the recesses 80, 81, 82 and 83, the holder 5 or rather its supporting body 13 can be designed in a more lightweight and more material-saving way. Similar to the holder according to FIG. 11, a hook 26 sticks out from the contact surface 15 a, b of the holder 5 again. The holder 5 also comprises a recess 27 being designed in form of an undercut of the hook 26, wherein the upper side of the recess 27 opposite to the flank 28 is comparably formed by a snap-fit hook 33. The snap-fit hook 33 is integrally attached at the bottom area of the hook 26 and, in this embodiment, is inclined by an angle of about 15° with respect to the contact surface 15 a, b. Furthermore, the snap-fit hook 33 is again received within a recess 50 in the supporting body 13, wherein the recess 50 is open to the contact surface 15 b. Similarly to the cross rail according to FIG. 4, the cross rail 2 of the mounting system according to FIG. 14 and FIG. 15 comprises a trapezoid-like cross section, having a top chord 24 and a broader bottom chord 23 being parallel thereto as well as having two bars 22 directed slantingly inwards. Additionally, in the upper area of the cross rail 2 between its supporting surface 19 a, b and the top chord 24, there is again provided an undercut longitudinal groove 20 having an opening slot that is relatively broad here. The overhang of the undercut longitudinal groove 20 provided at the left side operates as the protrusion 29 for the recess 27 of the hook 26. The maximum engagement between the recess 27 and the protrusion 29 is, in this embodiment, larger than one centimeter, wherein there is a sliding fit for deviations from the nominal distances within the desired compensation range provided between the contact surface 15 a, b as well as the diagonally opposite flank 28 on the side of the holder 5 and the supporting surface 19 a, b as well as the opposite flank 30 on the side of the cross rail 2. In the area of the protrusion 29, one section of the supporting surface 19 b is designed as the row 34 of teeth interacting with the snap-fit hook 33 and forming an snap-fit connection therewith, the snap-fit connection having several joining positions successing in the direction of the arrow 7. The direction of the arrow 7 again represents the direction of the downwardly running outer edges of the PV modules 1 and/or of the direction of the downhill force thereof. Opposite to the embodiment according to FIG. 5, the row 34 of teeth is designed in a slightly inclined manner and thus at the same time it operates as an insertion slant for the snap-fit hook 33. Instead of using a separate spring element such as in case of the holder according to FIG. 5, the latch 35 in this embodiment itself consists of an elastic material, in particular of EPDM rubber, wherein the latch 35 is mounted in the area of its recess such that latch 35 can be turned in by elastic self-deformation and accordingly turn out automatically. Furthermore, the holder 5 is substantially embodied as an extrusion molded part, as stated above. This means that the latter including the recesses 80, 81, 82 and 83, the hook 26 and the snap-fit hook 33 can be manufactured by means of cutting off from a correspondingly extrusion molded profile and almost without any post-processing. Only the latch 35 that is also embodied as an extruded part has to be manufactured separately and has to be inserted into the recess 50 within the holder 5. 

1. A mounting system for photovoltaic modules, in particular for frameless thin-film moduls, having two or more profile-shaped cross rails (2) which are arranged parallel to and at a distance to each other and which are provided to hold several PV modules, wherein each of the cross rails (2) comprises a plane supporting surface (19 a, b), and comprising several holders (5) which are each fixed or fixable to the back side of a PV module (1) by using an adhesive agent (12), wherein the PV module (1) can be mounted to the cross rails (2) by means of the holders (5), for which purpose each cross rail (2) has at least one holder (5) associated therewith and either each holder (5) has a recess (27) and each cross rail (2) has an integrated protrusion (29) or each holder (5) has a protrusion and each cross rail (2) has an integrated recess, wherein, for mounting, the PV module (1) is first placed on the cross rails (2) so that the holders (5) lay flat on the supporting surfaces (19 a, b) of cross rails (2), and secondly, while laying thereon, are shifted in a joining direction (7) perpendicular to the cross rails (2), wherein the recesses (27) and the protrusions (29) engage with each other, and a retaining safety device (33, 34, 35, 38, 60, 61, 70, 71) is provided between at least one cross rail (2) and a holder (5) associated therewith, said retaining safety device (33, 34; 35, 38; 60, 61; 70, 71) counteracting a shift of the holder (5) against the joining direction (7, 41).
 2. The mounting system according to claim 1, characterized that the adhesive agent (12) is a silicone-based adhesive.
 3. The mounting system according to claim 1, characterized that the adhesive agent (12) is a support layer double-sided covered with adhesive.
 4. The mounting system according to claim 1, characterized that the holders (5) are arranged at a distance from the outer contour (4) of the PV module (1) at positions within the inner surface area of the back side (11) of the PV module (1).
 5. The mounting system according to claim 4, characterized that the positions are selected such that the PV module (1) undergoes a minimum deflection in its position of use.
 6. The mounting system according to claim 4, characterized that exactly four holders (5) are provided for the PV module (1) and that the holders (5) are spaced inwardly from the outer edges of the PV module (1) at a distance of 17% to 27% of the distance towards the respective opposite outer edge.
 7. The mounting system according to any one of claims 4 to 6, characterized that a mounting template (8) is provided determining the positions for arranging the holders (5) relative to the outer contour (4) of the PV module (1).
 8. The mounting system according to claim 1, characterized that the holders (5) each comprise a flat supporting body (13) having a contact surface (15 a, b) and an adhesion surface (14) parallel thereto.
 9. The mounting system according to claim 8, characterized that the adhesion surface (14) has a rectangular format, which longer side is aligned in parallel to a longitudinal side of the PV module (1).
 10. The mounting system according to claim 8, characterized that the adhesion surface (14) has a square or circular format.
 11. The mounting system according to any one of claims 8 to 10, characterized that the flat supporting body (13) narrows towards the outer edges of the adhesion surface (14).
 12. The mounting system according to anyone of claims 8 to 11, characterized that the flat supporting body (13) has a trapezoid-like cross section or is formed similar to a truncated pyramid or a truncated cone.
 13. The mounting system according to claim 1, characterized that the supporting surfaces (19 a, b) of the cross rails (2) build a common inclined plane and the joining direction (7) running downwards parallel to the said plane.
 14. The mounting system according to claim 1, characterized that the recess (27) of the holder (5) or the recess of the cross rail is designed as an indentation of a hook (26).
 15. The mounting system according to claim 1, characterized that the protrusion of the cross rail or the protrusion of the holder is designed as an overhang of an undercut groove.
 16. The mounting system according to claim 14, characterized that the hook (26) of the holder (5) sticks out from the holder's contact surface (15 a, b), or the hook of the cross rail sticks out from the cross rail's supporting surface.
 17. The mounting system according to claim 15, characterized that the opening slot of the undercut groove of a holder divides the contact surface of said holder, or the opening slot of the undercut groove (20) of a cross rail (2) divides the contact surface (19 a, b) of said cross rail (2).
 18. The mounting system according to claim 1, characterized that the recesses (27) and the protrusions (29) engage with each other in a form-fitting manner when shifting in joining direction (7).
 19. The mounting system according to claim 1, characterized that the recesses (27) and the protrusions (29) engage with each other in a force-transmitting and form-fitting manner when shifting in joining direction (7).
 20. The mounting system according to any one of the preceding claims, further comprising a sliding fit (15 b, 28; 19 b, 30), the sliding fit (15 b, 28; 19 b, 30) is arranged between the contact surface (15 a, b) and an opposite flank (28) arranged parallel thereto at the protrusion or at the recess (27) of the holder (5), on the one hand, and the plane supporting surface (19 a, b) and an opposite flank (30) arranged parallel thereto at the protrusion (29) or at the recess of the cross rail (2), on the other hand.
 21. The mounting system according to claim 1, characterized that the maximum engagement between the recess (27) and the protrusion (29) is at least 4 mm.
 22. The mounting system according to claim 1, for retaining safety in an arresting manner further comprises a snap-fit connection disposed between at least one cross rail (2) and a holder (5) associated therewith and having several successive joining positions.
 23. The mounting system according to the preceding claim, characterized that the snap-fit connection is operating against the joining direction (7) in a blocking manner.
 24. The mounting system according to any one of claim 22 or 23, characterized that the snap-fit connection comprises a row (33, 34) of teeth integrated into the cross rail (2) and a snap-fit hook (33) elastically arranged at the holder (5), wherein the snap-fit hook (33) is interacting with the row (33, 34) of teeth.
 25. The mounting system according to to the preceding claim, characterized that the snap-fit hook (33) is arranged at a hook (26) sticking out from the contact surface (15 a, b) or is arranged in the area of said hook, and the row (34) of teeth is arranged at the bottom of an undercut groove (20) of the cross rail (2).
 26. The mounting system according to anyone of claim 22 or 23, characterized that the snap-fit connection comprises at least one elevation (60, 70) being integrated within the cross rail and a row (61, 71) of teeth being elastically arranged at the holder and interacting with the at least one elevation (60, 70).
 27. The mounting system to any one of claims 22 to 26, characterized that the elements (33, 34, 60, 61, 70, 71) of the snap-fit connection are arranged at flanks of the protrusion (29) and/or of the recess (27), and/or are arranged such the they limit the protrusion (29) and/or the recess (27).
 28. The mounting system according to any one of claims 22 to 27, characterized that an elastic element (73) of the snap-fit connection (70, 71, 73) clamps the holder (5) against the supporting area (19 a, b) of the cross rail (2).
 29. The mounting system according to claim 1, for retaining safety in a blocking manner further comprises a blocking element (35) disposed at at least one of the holders (5), wherein the blocking element (35), in a release position, allows a shift of the holder (5) on the supporting surface (19 a, b) of the cross rail (2) associated therewith into the joining direction (7), and, in a blocking position, blocks a shift against the joining direction (7).
 30. The mounting system according to the preceding claim, characterized that the blocking element (35) is a latch (35) arranged at the holder (35), the latch (35) is interacting with a limit stop (38) at the cross rail (2).
 31. The mounting system according to the preceding claim, characterized that the latch (35), in the release position, is turned into a recess (36) arranged within the contact surface (15 a) of the holder (5) and, in the blocking position, can abut against the limit stop (35) of the cross rail (2).
 32. The mounting system according to claim 28, characterized that the limit stop (38) is arranged at the undercut groove (20) of the cross rail (2).
 33. The mounting system according to claim 1, characterized that exactly two cross rails (2) are provided and, per cross rail (2) one, two or three holders (5) are provided which are fixed to the back side of the PV module (1).
 34. The mounting system according to claim 1, characterized that one or two further cross rails (2) are provided and, per cross rail (2), up to five holders (5) are provided which are fixed to the back side of the PV module (1).
 35. The mounting system according to claim 1, characterized that the cross rail (2) comprises a trapezoid-like hollow section with two slant bars (22).
 36. The mounting system according to the preceding claim, characterized that the slant bars (22) intersect in their extension in an intersection line (25) in or close to the supporting surface (19 a, b).
 37. The mounting system according to the preceding claim, characterized that the supporting surface (19 a, b) extending on both sides of the intersection line (25).
 38. The mounting system according to any one of the preceding claims, characterized that the holders (5) are designed substantially as extrusion molded parts.
 39. The mounting system according to any one of the preceding claims, characterized that the joining direction (7, 41) is aligned into the direction of the downhill force of the PV modules (1) and/or to the outer edges of the PV modules (1) running downwards.
 40. A holder of the mounting system according to anyone of claims 1 to
 39. 41. A cross rail of the mounting system according to anyone of claims 1 to
 39. 42. A mounting template (8) of the mounting system according to claim
 7. 43. An assembly group consisting of the PV module (1) and the holders (5) of the mounting system according to any one of claims 1 to 39, wherein the holders (5) are adhesively affixed to the back side of the PV module (1).
 44. An arrangement of the mounting system according to anyone of claims 1 to 39, characterized that the cross rails (2) are arranged stationary and the PV module (1) is engaged into the cross rails (2) by means of the holders (5). 